hhmmm. ive been looking at this thread several times now and hoping each time to find some time to critique, but i havent had the time to put into it, but now i think i do, plus i see its motion and i figured that youre now going to need some better critique to improve to the *dun dun dun* "next level!"...
looking at the static sprite first, the design is fundamentally alright, i kindof like the idea that hes sort of alienesque. Im comparing the first version you did vs the makeover, i have to say i like the proportion of the very first rendition better. i think the torso looks a little thick and perhaps the limbs slightly too long or wide to correlate with the sizes of the pocket fighter style. I think the pants on the newest rendition is probably the strongest part about it, it has a very clean feel at 1x zoom, though even still it has some 'loose pixels' that could use some smoothing out.
His feet... well, its hard to describe it, but as they stand now they kindof look like they just got ran over by a humvee man. take a look at the formity of the feet of the pocket fighter avatar of yours (even though i think their feet are longer and loook very slightly ran over as well to some degree, perhaps too 'long'). Even though your old version had no toes i liked the overall foot shape a lot better. The anatomy of the arms looks a bit generic at this point, id like to see a little definition in the knuckles or the shoulder bulge in the arm (which as it stands now looks like the shoulders come all the way down to where the mid to lower bicep should be ending).
i think the main thing id say could be improved is the level/depth of shading involved with the sprite. I would expect this version to be the beginning of the 'laying down basic light sources' step in the process of making an image (assuming it were done step by step in such a manner). Other than that, no real detail has been established, and i realize that this is somewhat remniscient of how pocket fighter sprites come across, but even then their art has a strong sense of line variation, stye, and ample contrast throughout the image. I think by comparison, this blue dude looks a bit 'light', there are a good number of midtones, but no real highlights or shadow values which would otherwise give him a nice sense of form and depth.
and actually, since the animation doesnt really have much to do with the new rendition of the sprite i think ill hold off on commenting on that for now.
my best advice would